KOSPI trips circuit breaker after 8% fall, Nikkei down 4.8% as AI chip selloff hits Asia; KSE-100 flat

South Korea's KOSPI fell about 8% on Thursday, 15 October 2026, tripping a circuit breaker that halted trading, while Japan's Nikkei 225 dropped 4.8% as a selloff in AI and chip stocks that began on Wall Street spread across Asia, Business Recorder reported, carrying Reuters. Back home, the KSE-100 held steady near 166,455 points at our 12:40pm PKT reading on our KSE-100 data page.

The numbers

• KOSPI: down 480.76 points to 5,528.05 by 03:38 GMT (8:38am PKT), its lowest since 29 July. It was the index's 10th circuit breaker this year and the 16th in its history, and a seventh straight losing session.
• Samsung Electronics fell 9.7% and SK Hynix 11.35%. Of 916 issues traded in Seoul, 855 fell.
• Foreign selling: foreigners sold a net 2.9 trillion won, about $2.15 billion (roughly Rs 595 billion at today's dollar rate).
• Nikkei 225: down 4.8% to 64,489.06 at the midday break; the broader Topix fell 2.5%, Business Recorder reported. Advantest lost 13.9%, SoftBank Group 9.4% and Tokyo Electron 7.3%. Drug makers rose, with Sumitomo Pharma up 13%.

Why markets fell

1. Hot US inflation: US consumer prices rose 3.7% in September, raising bets that the Federal Reserve will lift rates again and keep them high. Expensive, debt-funded tech stocks are hit hardest by that.
2. AI debt worries: reports of distressed debt at US cloud provider CoreWeave sent its shares down more than 15%, and Nomura's Wataru Akiyama said worries about AI companies' finances and spending had "risen quickly".
3. Wall Street first: the Nasdaq fell 1.9% on Wednesday and the Philadelphia Semiconductor Index 4.3%.

J.P. Morgan's Mixo Das said Seoul was "struggling to find a new buyer" now that share buybacks at Samsung and SK Hynix have ended, though he still expects AI stocks to be substantially higher in six to 12 months.

What it means in Pakistan

• PSX: the KSE-100 has little exposure to global tech and was almost flat (166,455 against 166,333 at the previous reading). Its bigger risks are oil and the rupee.
• Crypto: bitcoin was near $81,200 and ether near $2,370 on our bitcoin and ether pages, after $483 million of bets were wiped out on Wednesday.
• If you hold foreign shares through an app or a Roshan Digital Account, gains and losses in rupees depend on the dollar too: run the figures through our currency converter.

Earlier today we reported that SK Hynix fell 10% and SoftBank 7.9% on the same inflation fears.